1. Field of the Invention
The present invention relates to an illuminating device.
2. Description of the Related Art
In general, in an illuminating device using a light emitting diode (LED), the quality of light and the lifespan of the illuminating device are affected by the operating temperature thereof. Therefore, maintaining an appropriate operating temperature may be a very important factor in view of the initial quality and long-term reliability of an LED illuminating device.
In order to maintain the operating temperature of this illuminating device at an appropriate level, a method of manufacturing a heat sink having an extended heat radiating area through the use of a metal having high thermal conductivity, to thereby couple the manufactured heat sink to an LED module, may be commonly used.
However, an extended heat sink has a finite temperature difference and a constant thermal resistance between the heat absorbing surface and the heat radiating surface thereof, due to the finite thermal conductivity of a material used therefor. The temperature difference and thermal resistance may therefore cause an unnecessary rise in temperature in an LED illuminating device. In the case of manufacturing a heat sink having a large cross-sectional area in order to reduce the thermal resistance thereof, disadvantages such as increasing the weight and the costs of the illuminating device may be caused.
Accordingly, the necessity of providing a heat sink capable of reducing the thermal resistance between the heat absorbing surface and the heat radiating surface, while minimizing the use of a high density and expensive metal material has been raised. Furthermore, in order to maintain advantages such as a long illuminating device lifespan, a great deal of research into the structural improvement and reductions in the size and weight of the illuminating device, for more efficient heat radiation, have been undertaken.